In my pending applications Ser. No. 631,991, now U.S. Pat. No. 4,577,841 filed July 18, 1984 and Ser. No. 675,892, filed Nov. 28, 1984, there are shown and described spring units for supporting a grid frame for yield relative to a base frame. In Ser. No. 631,991, each spring unit comprises top and bottom attaching elements held in spaced relation by oppositely-facing, generally U-shaped structures and in Ser. No. 675,892, the top and bottom attaching elements are held in spaced relation by generally V-shaped structures. The arms of the U-shaped and V-shaped supporting structures are relatively long, hence, the yield is relatively soft. The structure according to the instant invention is designed to provide a configuration which will afford stiffer yield without having to increase the gage of the wire of which the spring units are comprised.